The alert states that information suggests ISIS, al-Qaida, Boko Haram and other terrorist groups are planning attacks in multiple regions.

"Authorities believe the likelihood of terror attacks will continue as members of ISIL/Da’esh return from Syria and Iraq," the State Department said in the alert. "Additionally, there is a continuing threat from unaffiliated persons planning attacks inspired by major terrorist organizations but conducted on an individual basis. Extremists have targeted large sporting events, theatres, open markets, and aviation services."

Travelers are recommended to be aware of their surroundings and avoid large crowds and crowded places, such as holiday festivals and events. The State Department also suggests:

Follow the instructions of local authorities. Monitor media and local information sources and factor updated information into personal travel plans and activities.

Be prepared for additional security screening and unexpected disruptions.

Stay in touch with your family members and ensure they know how to reach you in the event of an emergency.

If you are flying this Thanksgiving holiday, there are some additional changes you will need to know about as well. The Transportation Security Administration has announced a major change in how long you might have to wait in order to get on your plane.

It all stems from heightened security procedures after recent terror attacks across the world.

The TSA said that they are now doubling their official recommendation of passenger airport arrival times – going from one hour before a flight leaves to two hours.

Meanwhile, the Metropolitan Washington Airports Authority (MWAA) is advising international travelers to increase their arrival times from two to three hours prior to takeoff.

Three days before the holiday at Reagan National Airport, the MWAA Police Department has officers in dark green military style uniforms with long guns patrolling the outside the airport. Department of Homeland Security is also here with their Explosives Detection K-9 Team parked out front.

Inside, police officers on hybrid bikes and on foot patrol are making rounds in the terminals.

Passengers we spoke with at Reagan said they appreciate the added protection, and while the extra security has heightened their awareness this Thanksgiving travel season, nobody said they would change their plans.

One of the biggest things that holds up the security lines here are people trying to bring prohibited items through TSA checkpoints. They said if they can cut down on that, they can cut down on wait times.

TSA is now trying out some new ways to keep you updated. One of them is a new web tool called "Can I bring?" that you can find on the TSA’s website and app. All you do is just type in an item, hit enter and it will tell you if you can bring it through a checkpoint.

The other way is a new Twitter handle @AskTSA. It is staffed by a live TSA official who will respond real-time to questions, complaints and problems at the airport.

TSA spokesperson Lisa Farbstein said the idea is to solve problems and answer questions before they wind up at the checkpoint.

"It’s been pretty eye-opening I think for the travelers and for us,” said Farbstein. “We are getting a better idea of the types of concerns people have right then and there, and we're trying to see what we can do to mitigate it if that's the case.”

There is also a big logistical component to the arrival times here. Airport officials said they expect parking to be in high demand over the next week, so when you factor in that two-hour extra security window, you also need to check on the airport’s website and add in additional time to find parking.